Thermoplastic Resin Composition and Molded Article Produced Therefrom

ABSTRACT

A thermoplastic resin composition includes: about 100 parts by weight of a base resin including about 14 wt % to about 25 wt % of (A) a (meth)acrylate-aromatic vinyl-vinyl cyanide copolymer and about 75 wt % to about 86 wt % of (B) a (meth)acrylate resin; and about 25 parts by weight to about 35 parts by weight of (C) an antistatic resin including at least one of a polyether-ester amide block copolymer, a poly(alkylene) glycol and a polyamide, relative to about 100 parts by weight of the base resin.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority under 35 USC Section 119 to and thebenefit of Korean Patent Application 10-2016-0184438, filed on Dec. 30,2016, the entire disclosure of which is incorporated herein byreference.

FIELD

The present invention relates to a thermoplastic resin composition and amolded article produced therefrom.

BACKGROUND

Thermoplastic resins have good properties in terms of mechanicalproperties, processability, appearance and the like, and thus are widelyused for interior/exterior materials of electric/electronic products,interior/exterior materials for automobiles, exterior materials forbuilding, and the like.

Recently, there is an increasing market trend of using transparent ortranslucent materials in products such as household appliances, medicaldevices, toys and the like, and demand for high impact properties andhigh flowability increases with increasing level of difficulty indesign.

Typically, it is known to use an impact modifier such as a siliconecompound for reinforcement of impact resistance of a thermoplasticresin. However, a thermoplastic resin composition including an impactmodifier can exhibit low flowability or can suffer from whitening on aproduct when left at low temperature.

Moreover, since a thermoplastic resin including an excess of an impactmodifier is likely to suffer from generation of scratches and has highhaze and low total light transmittance, it is difficult to use such athermoplastic resin in products requiring transparency.

Therefore, there is increasing demand for a thermoplastic resincomposition, which has good surface resistance properties, antibacterialproperties and the like while securing high transparency and impactresistance and thus can be applied to various products such as householdappliances, office automation equipment, medical devices, toys, and thelike.

SUMMARY OF THE INVENTION

Embodiments provide a thermoplastic resin composition that can have goodtransparency, antistatic properties, impact resistance and/orantibacterial properties (activity), and a molded article producedtherefrom.

The thermoplastic resin composition includes: about 100 parts by weightof a base resin including about 14% by weight (wt %) to about 25 wt % of(A) a (meth)acrylate-aromatic vinyl-vinyl cyanide copolymer and about 75wt % to about 86 wt % of (B) a (meth)acrylate resin; and about 25 partsby weight to about 35 parts by weight of (C) an antistatic resinincluding at least one of a polyether-ester amide block copolymer, apoly(alkylene) glycol and a polyamide, relative to about 100 parts byweight of the base resin.

A weight ratio of the (A) (meth)acrylate-aromatic vinyl-vinyl cyanidecopolymer to the (B) (meth)acrylate resin in the base resin may rangefrom about 1:3 to about 1:6.

The (A) (meth)acrylate-aromatic vinyl-vinyl cyanide copolymer may be acopolymer of a mixture including about 20 wt % to about 40 wt % of anaromatic vinyl monomer and a vinyl cyanide monomer and about 60 wt % toabout 80 wt % of a (meth)acrylate monomer.

The (C) antistatic resin may include a polyether-ester amide blockcopolymer.

The polyether-ester amide block copolymer may include about 10 wt % toabout 95 wt % of a polyether-ester block.

The base resin may have an index of refraction of about 1.25 to about1.75.

In the thermoplastic resin composition, a difference in index ofrefraction between the base resin and the antistatic resin may be about0.3 or less, as represented by Equation 1:

Difference in index of refraction=|(R1−R2)|[Equation 1]

where R1 is an index of refraction of the base resin and R2 is an indexof refraction of the antistatic resin.

The thermoplastic resin composition may have an antibacterial activityof about 2.0 to about 7.0 against Staphylococcus and an antibacterialactivity of about 1.0 to about 7.5 against Escherichia coli, ascalculated by Equation 2 after a 5 cm×5 cm specimen is inoculated withStaphylococcus and Escherichia coli in accordance with JIS Z 2801 forantibacterial evaluation:

Antibacterial activity=log(M1/M2)  [Equation 2]

where M1 is the number of bacteria measured on a blank specimen afterculturing at 35° C. and 90% RH for 24 hours and M2 is the number ofbacteria measured on the specimen of the thermoplastic resin compositionafter culturing at 35° C. and 90% RH for 24 hours.

The thermoplastic resin composition may have a haze of about 10% or lessand a total light transmittance of about 80% or more, as measured on a2.5 mm thick specimen in accordance with ASTM D1003.

The thermoplastic resin composition may have a surface resistance ofabout 10×10⁸Ω/□ or less, as measured on a 2.5 mm thick specimen at 23°C. and 50% RH in accordance with ASTM D250.

The thermoplastic resin composition may satisfy Equation 3:

1000 mm≤Id  [Equation 3]

where Id is a drop height measured on a 2 mm thick injection-moldedspecimen using a 1 kg metallic weight according to the DuPont drop testmethod.

Another embodiment relates to a molded article produced from thethermoplastic resin composition set forth above.

DETAILED DESCRIPTION

The above and other aspects, features, and advantages of the presentinvention will become apparent from the detailed description of thefollowing embodiments. It should be understood that the presentinvention is not limited to the following embodiments and may beembodied in different ways by those skilled in the art without departingfrom the scope of the present invention. Rather, the embodiments areprovided for complete disclosure and to provide thorough understandingof the present invention by those skilled in the art. The scope of thepresent invention should be defined only by the appended claims.

One embodiment of the present invention relates to a thermoplastic resincomposition, which includes: about 100 parts by weight of a base resinincluding about 14 wt % to about 25 wt % of (A) a(meth)acrylate-aromatic vinyl-vinyl cyanide copolymer and about 75 wt %to about 86 wt % of (B) a (meth)acrylate resin; and about 25 parts byweight to about 35 parts by weight of (C) an antistatic resin includingat least one of a polyether-ester amide block copolymer, apoly(alkylene) glycol and a polyamide, relative to about 100 parts byweight of the base resin.

The present invention provides a thermoplastic resin composition thatcan have good transparency, antistatic properties, impact resistanceand/or antibacterial properties. For example, the thermoplastic resincomposition can exhibit good property balance between transparency,antistatic properties, impact resistance and antibacterial properties,and thus can be more usefully industrially used when applied toproducts, such as household appliances, housings of office automationequipment, toys, and the like.

As used herein, unless otherwise defined, the term “substituted” meansthat a hydrogen atom in a functional group is substituted with one ormore of a halogen group, a C₁ to C₃₀ alkyl group, a C₁ to C₃₀ haloalkylgroup, a C₆ to C₃₀ aryl group, a C₂ to C₃₀ heteroaryl group, and/or a C₁to C₂₀ alkoxy group. Also as used herein, unless otherwise defined, theterm “hetero” refers to one or more of a S, N, O, and/or P atom in placeof a carbon atom.

(A) (Meth)Acrylate-Aromatic Vinyl-Vinyl Cyanide Copolymer

According to embodiments of the present invention, the(meth)acrylate-aromatic vinyl-vinyl cyanide copolymer is obtained bycopolymerization of a vinyl cyanide monomer, an aromatic vinyl monomerand a (meth)acrylate monomer, and can improve flowability, thermalstability and/or compatibility of the thermoplastic resin compositionwhile realizing transparency and/or impact resistance thereof.

The (meth)acrylate-aromatic vinyl-vinyl cyanide copolymer may be anon-rubbery copolymer not including a rubber polymer.

In one embodiment, the (meth)acrylate-aromatic vinyl-vinyl cyanidecopolymer may be prepared by a general process of polymerizing a mixtureof the vinyl cyanide monomer, the aromatic vinyl monomer and the(meth)acrylate monomer in conjunction with a polymerization initiator.

The initiator may be a radical polymerization initiator, without beinglimited thereto. Examples of the initiator may include, for example,peroxides, persulfates, azo cyanide compounds, and/or redox initiators,without being limited thereto. In addition, polymerization of thecopolymer may be performed by a polymerization method known in the art,such as emulsion polymerization, suspension polymerization, bulkpolymerization, and the like.

In one embodiment, the vinyl cyanide monomer may include at least one ofacrylonitrile, methacrylonitrile, ethacrylonitrile, phenylacrylonitrile, α-chloroacrylonitrile, and fumaronitrile, without beinglimited thereto. These vinyl cyanide monomers may be used alone or incombination thereof.

In one embodiment, the vinyl cyanide monomer may be present in an amountof about 1 wt % to about 50 wt %, for example, about 5 wt % to about 45wt %, and as another example about 10 wt % to about 30 wt %, based onthe total weight (100 wt %) of the (meth)acrylate-aromatic vinyl-vinylcyanide copolymer. In some embodiments, the (meth)acrylate-aromaticvinyl-vinyl cyanide copolymer may include the vinyl cyanide monomer inan amount of about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33,34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or 50 wt%. Further, according to some embodiments, the amount of the vinylcyanide monomer can be in a range from about any of the foregoingamounts to about any other of the foregoing amounts. Within this range,the thermoplastic resin composition can have good properties in terms offlowability, impact resistance, appearance, and the like.

In one embodiment, the aromatic vinyl monomer may include, for example,styrene, α-methylstyrene, β-methylstyrene, p-methylstyrene,p-t-butylstyrene, ethylstyrene, vinylxylene, monochlorostyrene,dichlorostyrene, dibromostyrene, and vinylnaphthalene, without beinglimited thereto. These aromatic vinyl monomers may be used alone or incombination thereof. In one embodiment, the aromatic vinyl monomer maybe present in an amount of about 1 wt % to about 50 wt %, for example,about 5 wt % to about 45 wt %, and as another example about 10 wt % toabout 30 wt %, based on the total weight (100 wt %) of the(meth)acrylate-aromatic vinyl-vinyl cyanide copolymer. In someembodiments, the (meth)acrylate-aromatic vinyl-vinyl cyanide copolymermay include the aromatic vinyl monomer in an amount of about 1, 2, 3, 4,5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23,24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41,42, 43, 44, 45, 46, 47, 48, 49, or 50 wt %. Further, according to someembodiments, the amount of the aromatic vinyl monomer can be in a rangefrom about any of the foregoing amounts to about any other of theforegoing amounts. Within this range, the thermoplastic resincomposition can have further improved properties in terms of heatresistance, impact resistance, and the like.

In one embodiment, the (meth)acrylate monomer may include substituted orunsubstituted acrylic acids, methacrylic acids, alkyl esters thereof,and the like. These (meth)acrylate monomers may be used alone or incombination thereof. In one embodiment, the (meth)acrylate monomer mayinclude at least one of substituted or unsubstituted C₁ to C₂₀ linear orbranched alkyl (meth)acrylic acid esters, for example, methyl(meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl(meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl(meth)acrylate, ethylhexyl (meth)acrylate, octyl (meth)acrylate, nonyl(meth)acrylate, decyl (meth)acrylate, and esters thereof, without beinglimited thereto. These (meth)acrylate monomers may be used alone or incombination thereof.

In one embodiment, the (meth)acrylate monomer may be present in anamount of about 10 wt % to about 90 wt %, for example, about 40 wt % toabout 80 wt %, and as another example about 60 wt % to about 80 wt %,based on the total weight (100 wt %) of the (meth)acrylate-aromaticvinyl-vinyl cyanide copolymer. In some embodiments, the(meth)acrylate-aromatic vinyl-vinyl cyanide copolymer may include the(meth)acrylate monomer in an amount of about 10, 11, 12, 13, 14, 15, 16,17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34,35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52,53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70,71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88,89, or 90 wt %. Further, according to some embodiments, the amount ofthe (meth)acrylate monomer can be in a range from about any of theforegoing amounts to about any other of the foregoing amounts. Withinthis range, the thermoplastic resin composition can have furtherimproved properties in terms of impact resistance, flowability,appearance, and the like.

In one embodiment, the (meth)acrylate-aromatic vinyl-vinyl cyanidecopolymer may be a copolymer of a mixture including about 20 wt % toabout 40 wt % of the aromatic vinyl monomer and the vinyl cyanidemonomer and about 60 wt % to about 80 wt % of the (meth)acrylatemonomer. Within this range, the thermoplastic resin composition can havefurther improved properties in terms of impact resistance, flowability,appearance, and the like.

In some embodiments, the (meth)acrylate-aromatic vinyl-vinyl cyanidecopolymer may include a mixture of the aromatic vinyl monomer and thevinyl cyanide monomer in an amount of about 20, 21, 22, 23, 24, 25, 26,27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, or 40 wt %. Further,according to some embodiments, the amount of the mixture of the aromaticvinyl monomer and the vinyl cyanide monomer can be in a range from aboutany of the foregoing amounts to about any other of the foregoingamounts.

In some embodiments, the (meth)acrylate-aromatic vinyl-vinyl cyanidecopolymer may include the (meth)acrylate monomer in an amount of about60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77,78, 79, or 80 wt %. Further, according to some embodiments, the amountof the (meth)acrylate monomer can be in a range from about any of theforegoing amounts to about any other of the foregoing amounts.

In one embodiment, the (meth)acrylate-aromatic vinyl-vinyl cyanidecopolymer may have a weight average molecular weight of about 30,000g/mol to about 200,000 g/mol, for example about 35,000 g/mol to about150,000 g/mol, and as another example about 40,000 g/mol to about110,000 g/mol. Within this range, the thermoplastic resin compositioncan have further improved properties in terms of thermal stability, heatresistance, and/or flowability.

The (meth)acrylate-aromatic vinyl-vinyl cyanide copolymer is present inan amount of about 14 wt % to about 25 wt % based on 100 wt % of thebase resin. In some embodiments, the base resin may include the(meth)acrylate-aromatic vinyl-vinyl cyanide copolymer in an amount ofabout 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 wt %. Further,according to some embodiments, the amount of the (meth)acrylate-aromaticvinyl-vinyl cyanide copolymer can be in a range from about any of theforegoing amounts to about any other of the foregoing amounts. If theamount of the (meth)acrylate-aromatic vinyl-vinyl cyanide copolymer isless than about 14 wt %, it can be difficult to realize thermalstability, impact resistance and the like, and if the amount of the(meth)acrylate-aromatic vinyl-vinyl cyanide copolymer is greater thanabout 25 wt %, it can be difficult to realize transparency of thethermoplastic resin composition and antistatic properties thereof can beinsufficient.

In one embodiment, the (meth)acrylate-aromatic vinyl-vinyl cyanidecopolymer may be present in an amount of about 14 wt % to about 20 wt %,for example about 15 wt % to about 19 wt %. Within this range, thethermoplastic resin composition can have further improved properties interms of impact resistance, transparency, antistatic properties, and thelike.

(B) (Meth)Acrylate Resin

The (meth)acrylate resin (which is not the same as the(meth)acrylate-aromatic vinyl-vinyl cyanide copolymer) is a polymer of a(meth)acrylate monomer and may include a homopolymer of one(meth)acrylate monomer and/or a copolymer including two or more(meth)acrylate monomers as polymerization units. With these components,the thermoplastic resin can realize good transparency and/or improvedproperties such as impact resistance and the like.

In one embodiment, the (meth)acrylate monomer may include at least oneof substituted or unsubstituted C₁ to C₂₀ linear or branched alkyl(meth)acrylic acid esters, for example, methyl (meth)acrylate, ethyl(meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl(meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, ethylhexyl(meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, decyl(meth)acrylate, and esters thereof, without being limited thereto. These(meth)acrylate monomers may be used alone or in combination thereof. Inone embodiment, the (meth)acrylate monomer may include methylmethacrylate and/or methyl acrylate, and the like. In this embodiment,the (meth)acrylate monomer acts in combination with the(meth)acrylate-aromatic vinyl-vinyl cyanide copolymer set forth above,whereby transparency and impact resistance of the base resin can befurther improved while allowing adjustment of the index of refractionthereof. The (meth)acrylate resin may be present in an amount of about75 wt % to about 86 wt % based on 100 wt % of the base resin. In someembodiments, the base resin may include the (meth)acrylate resin in anamount of about 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, or 86 wt %.Further, according to some embodiments, the amount of the (meth)acrylateresin can be in a range from about any of the foregoing amounts to aboutany other of the foregoing amounts. If the amount of the (meth)acrylateresin is less than about 75 wt %, the thermoplastic resin compositioncan have low total light transmittance due to high haze and thus isunlikely to realize a transparent appearance, and if the amount of the(meth)acrylate resin is greater than about 86 wt %, the thermoplasticresin composition can have insufficient antistatic properties due tohigh surface resistance and thus is unlikely to realize good impactresistance.

In one embodiment, the (meth)acrylate resin may be present in an amountof about 78 wt % to about 85 wt %, for example about 80 wt % to about 85wt % in the base resin. Within this range, the thermoplastic resincomposition can have better impact resistance, transparency, antistaticproperties, and the like.

(C) Antistatic Resin

The antistatic resin may improve antibacterial properties, antistaticproperties and the like of the thermoplastic resin composition (or aspecimen produced therefrom), and may include at least one of apolyether-ester amide block copolymer, a poly(alkylene) glycol, and apolyamide.

In one embodiment, the (C) antistatic resin may include apolyether-ester amide block copolymer. In this embodiment, thethermoplastic resin composition can have further improved antibacterialproperties and antistatic properties and also can have improvedcompatibility with the base resin set forth above. The polyether-esteramide block copolymer may be a copolymer including a polyamide block, apolyester block, and an ether unit.

In one embodiment, the polyether-ester amide block copolymer may includea polyether-ester amide having a bisphenol skeleton such as bisphenol A,for example, a polyether-ester amide formed by bonding a polyamidehaving carboxyl groups at both ends thereof to a polyethylene oxide viabisphenol A glycidyl ether, or the like.

In one embodiment, the polyether-ester amide block copolymer may be ablock copolymer of a reaction mixture including: a C₆ or moreaminocarboxylic acid, lactam and/or diamine-dicarboxylic acid salt; apoly(alkylene) glycol; and a C₄ to C₂₀ dicarboxylic acid.

Examples of the C₆ or more aminocarboxylic acid, lactam and/ordiamine-dicarboxylic acid salt may include without limitation:aminocarboxylic acids such as ω-aminocaproic acid, ω-aminoenanthic acid,ω-aminocaprylic acid, ω-aminopelargonic acid, ω-aminocapric acid,1,1-aminoundecanoic acid, and 1,2-aminododecanoic acid; lactams such ascaprolactam, enanthic lactam, caprylic lactam, and lauryl lactam; andsalts of diamine and dicarboxylic acid such ashexamethylenediamine-adipic acid salt andhexamethylenediamine-isophthalic acid salt; and the like, and mixturesthereof. For example, the C₆ or more aminocarboxylic acid, lactam and/ordiamine-dicarboxylic acid salt may be 1,2-aminododecanoic acid,caprolactam, and/or hexamethylenediamine-adipic acid salt.

Examples of the poly(alkylene) glycol may include without limitationpolyethylene glycol, poly(1,2-propylene) glycol, poly(1,3-propylene)glycol, polytetramethylene glycol, polyhexamethylene glycol, a blockand/or random copolymer of ethylene glycol and propylene glycol, and/ora copolymer of ethylene glycol and tetrahydrofuran. For example, thepoly(alkylene) glycol may be polyethylene glycol and/or a copolymer ofethylene glycol and propylene glycol.

Examples of the C₄ to C₂₀ dicarboxylic acid may include withoutlimitation terephthalic acid, 1,4-cyclohexarboxylic acid, sebacic acid,adipic acid, dodecane carboxylic acid, and the like, and combinationsthereof.

In one embodiment, a bond between the C₆ or more aminocarboxylic acid,lactam and/or diamine-dicarboxylic acid salt and the poly(alkylene)glycol may be an ester bond; a bond between the C₆ or moreaminocarboxylic acid, lactam and/or diamine-dicarboxylic acid salt andthe C₄ to C₂₀ dicarboxylic acid may be an amide bond; and a bond betweenthe poly(alkylene) glycol and the C₄ to C₂₀ dicarboxylic acid may be anester bond.

In one embodiment, the polyether-ester amide block copolymer may includeabout 10 wt % to about 95 wt %, for example about 15 wt % to about 90 wt%, and as another example about 20 wt % to about 85 wt % of thepolyether-ester block. In some embodiments, the polyether-ester amideblock copolymer may include the polyether-ester block in an amount ofabout 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43,44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61,62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79,80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, or 95 wt %.Further, according to some embodiments, the amount of thepolyether-ester block can be in a range from about any of the foregoingamounts to about any other of the foregoing amounts. Within this range,the thermoplastic resin composition can have further improved propertiesin terms of mechanical properties, antibacterial properties, antistaticproperties, and the like.

In one embodiment, the antistatic resin is present in an amount of about25 parts by weight to about 35 parts by weight relative to about 100parts by weight of the base resin. In some embodiments, the base resinmay include the antistatic resin in an amount of about 25, 26, 27, 28,29, 30, 31, 32, 33, 34, or 35 parts by weight. Further, according tosome embodiments, the amount of the antistatic resin can be in a rangefrom about any of the foregoing amounts to about any other of theforegoing amounts. If the amount of the antistatic resin is less thanabout 25 parts by weight, there is a concern that the thermoplasticresin composition can have poor antibacterial properties and/orantistatic properties, and if the amount of the antistatic resin isgreater than about 35 parts by weight, the thermoplastic resincomposition can exhibit insufficient impact resistance, and can havehigh haze and/or low total light transmittance, thereby providing a poorappearance.

In one embodiment, the antistatic resin may be present in an amount ofabout 27 parts by weight to about 33 parts by weight, for example about28 parts by weight to about 32 parts by weight, relative to about 100parts by weight of the base resin. Within this range, the thermoplasticresin composition can have further improved properties in terms ofimpact resistance, transparency, antistatic properties, and the like.

(D) Additives

The thermoplastic resin composition may further include one or more oftypical additive(s) included in thermoplastic resin compositions.Examples of the additives may include flame retardants, fillers,antioxidants, anti-dripping agents, lubricants, release agents,nucleating agents, stabilizers, pigments, dyes, and combinationsthereof, without being limited thereto. The additives may be present inan amount of about 0.001 parts by weight to about 40 parts by weight,for example, about 0.1 parts by weight to about 10 parts by weight,relative to about 100 parts by weight of the thermoplastic resincomposition.

In the thermoplastic resin composition according to the presentinvention, a weight ratio of the (A) (meth)acrylate-aromatic vinyl-vinylcyanide copolymer to the (B) (meth)acrylate resin may range from about1:3 to about 1:6, for example from about 1:3 to about 1:5. In someembodiments, the weight ratio of the (A) (meth)acrylate-aromaticvinyl-vinyl cyanide copolymer to the (B) (meth)acrylate resin may be1:3, 1:4, 1:5, or 1:6. Within this range, the thermoplastic resincomposition can have a good balance between transparency, antistaticproperties, impact resistance, and/or antibacterial properties.

A difference in index of refraction between the base resin and theantistatic resin can be reduced due to combined action of the (A)(meth)acrylate-aromatic vinyl-vinyl cyanide copolymer and the (B)(meth)acrylate resin, whereby the thermoplastic resin compositionaccording to the present invention can exhibit low haze and furtherimproved total light transmittance, and thus can have better appearanceproperties.

The base resin may have an index of refraction of about 1.25 to about1.75, for example about 1.45 to about 1.55. Within this range, thethermoplastic resin composition can exhibit good optical properties suchas high transparency, high total light transmittance, and/or low haze.

In the thermoplastic resin composition according to the presentinvention, the difference in index of refraction between the base resinand the antistatic resin may be about 0.3 or less, for example about 0.2or less, and as another example about 0.15 or less, as represented byEquation 1:

Difference in index of refraction=|(R1−R2)|  [Equation 1]

where R1 is an index of refraction of the base resin and R2 is an indexof refraction of the antistatic resin. Thus, the thermoplastic resincomposition can exhibit further improved transparency and also can havebetter effects in reduction of haze and/or colorability when including ahigh amount of the antistatic resin.

The thermoplastic resin composition may be prepared in pellet or powderform by mixing the components set forth above, followed by meltextrusion at about 200° C. to about 280° C., for example, about 220° C.to about 250° C., using a general twin-screw extruder.

The thermoplastic resin composition according to the present inventionhas an antibacterial effect against various bacteria includingStaphylococcus, Escherichia coli, and the like.

In one embodiment, the thermoplastic resin composition may have anantibacterial activity of about 2.0 to about 7.0 against Staphylococcusand an antibacterial activity of about 1.0 to about 7.5 againstEscherichia coli, as calculated by Equation 2 after a 5 cm×5 cm specimenis inoculated with Staphylococcus and Escherichia coli, in accordancewith JIS Z 2801 for antibacterial evaluation:

Antibacterial activity=log(M1/M2)  [Equation 2]

where M1 is the number of bacteria measured on a blank specimen afterculturing at 35° C. and 90% relative humidity (RH) for 24 hours and M2is the number of bacteria measured on the specimen of the thermoplasticresin composition after culturing at 35° C. and 90% RH for 24 hours.Thus, the thermoplastic resin composition can have good antibacterialproperties and thus can have advantageous properties for use inproducts, such as household appliances, toys, and the like.

In one embodiment, the thermoplastic resin composition may have a hazeof about 10% or less and a total light transmittance of about 80% ormore, as measured on a 2.5 mm thick specimen in accordance with ASTMD1003. Thus, the thermoplastic resin composition can have goodtransparency, and thus can have advantageous properties for use inhousehold appliances, toys, and various products requiring transparency.

In one embodiment, the thermoplastic resin composition may have asurface resistance of about 10×10⁸Ω/□ or less, as measured on a 2.5 mmthick specimen at 23° C. and 50% RH in accordance with ASTM D250. Thus,the thermoplastic resin composition can have good antistatic propertiesand voltage properties, and thus can have advantageous properties foruse in household appliances, office automation equipment, toys, andvarious products requiring good electrical properties.

In one embodiment, the thermoplastic resin composition may satisfyEquation 3:

1000 mm≤Id  [Equation 3]

where Id is a drop height measured on a 2 mm thick molded articlespecimen using a 1 kg metallic weight according to the DuPont drop testmethod. Thus, the thermoplastic resin composition can have good impactresistance and thus can have advantageous properties for use in variousproducts requiring impact resistance.

Another embodiment relates to a molded article produced from thethermoplastic resin composition set forth above. The antibacterialthermoplastic resin composition may be prepared in pellet form, and theprepared pellets may be manufactured into various molded articles(products) by various molding methods such as injection molding,extrusion, vacuum molding, casting, and the like. These molding methodsare well known by one of ordinary skill in the art.

The molded article produced from the thermoplastic resin compositionaccording to the present invention can have good transparency,antistatic properties, impact resistance, and/or antibacterialproperties, and a molded article made from the same can be used in theproduction of various products, including without limitation householdappliances, housings of office automation equipment, toys, and the like.

EXAMPLE

Next, the present invention will be described in more detail withreference to the following examples. However, it should be understoodthat these examples are provided for illustration only and are not to beconstrued in any way as limiting the present invention.

(A) (Meth)Acrylate-Aromatic Vinyl-Vinyl Cyanide Copolymer

(a1) 73.85 wt % of methyl methacrylate, 5 wt % of acrylonitrile, and21.15 wt % of styrene are introduced into a reactor, followed byperforming suspension polymerization, and then dehydrated and dried,whereby a methyl methacrylate-styrene-acrylonitrile copolymer having amolecular weight of about 105,000 g/mol is prepared in the form of beadsand used.

(B) (Meth)Acrylate Resin

A polymethylmethacrylate resin (model: TF-9, Lotte MRC Co., Ltd.) isused.

(C) Antistatic Resin

An antistatic resin (model: PELECTRON AS, Sanyo Co., Ltd.) including apolyether-ester amide block copolymer is used.

Example 1 and Comparative Examples 1 to 4: Preparation of ThermoplasticResin Composition

The components set forth above are introduced into a reactor in amountsas listed in Table 1, followed by performing extrusion at 230° C.,thereby preparing pellets. Extrusion is performed using a twin-screwextruder having L/D=36 and a diameter of 45 mm and the prepared pelletsare dried at 80° C. for 4 or more hours, followed by injection moldingin a 6 oz. injection molding machine (molding temperature: 250° C., moldtemperature: 60° C.), thereby manufacturing a specimen. The manufacturedspecimen is evaluated as to the following properties. Results are shownin Table 2.

TABLE 1 Comparative Comparative Comparative Comparative ComponentExample 1 Example 1 Example 2 Example 3 Example 4 (A) 17 56 56 43 30 (B)83 44 44 57 70 (C) 30 — 30 30 30

In Table 1, (A) and (B) are given in units of wt % based on the totalsum (100%) of (A)+(B), and (C) is given in unit of parts by weightrelative to 100 parts by weight of the sum total of (A)+(B).

Evaluation of Properties

(1) Haze (%) and Total light transmittance (%): Haze and total lighttransmittance are measured on a 2.5 mm thick injection-molded specimenusing a haze meter in accordance with ASTM D1003.

(2) Surface resistance (Ω/□): Surface resistance is measured on a 2.5 mmthick injection-molded specimen at 23° C. and 50% RH in accordance withASTM D250.

(3) Antibacterial activity: Antibacterial activity is calculated byEquation 2 after a 5 cm×5 cm specimen is inoculated with Staphylococcusand Escherichia coli, in accordance with JIS Z 2801 for antibacterialevaluation.

Antibacterial activity=log(M1/M2)  [Equation 2]

where M1 is the number of bacteria measured on a blank specimen afterculturing at 35° C. and 90% RH for 24 hours and M2 is the number ofbacteria measured on the specimen of the thermoplastic resin compositionafter culturing at 35° C. and 90% RH for 24 hours.

(4) DuPont drop test: According to the DuPont drop test, each of a 0.5kg rubbery weight and a 1 kg metallic weight is dropped 20 times onto a2 mm thick injection-molded specimen from a height of 1000 mm, followedby observing whether cracks are generated on the specimen. When thespecimen did not suffer from cracks and thus passed the DuPont droptest, the specimen is rated as O, and when the specimen suffers fromcracks and thus did not pass the DuPont drop test, the specimen is ratedas X.

(5) Appearance properties: When a specimen has a haze of 10% or less anda total light transmittance of 80% or more and thus has good appearanceproperties, the specimen is rated as O, and when a specimen has a hazeof greater than 10% and a total light transmittance of less than 80% andthus has insufficient appearance properties, the specimen is rated as X.

(6) Electrical properties: When a specimen has a surface resistance of10×10⁸Ω/□ or less and thus has electrical properties suitable to be usedfor purposes such as household appliances and the like, the specimen israted as O, and when a specimen has a surface resistance of greater than10×10⁸ Ω/□ and thus has electrical properties unsuitable for thepurposes set forth above, the specimen is rated as X.

(7) Impact resistance: According to the DuPont drop test, a 1 kgmetallic weight is dropped 20 times onto a 2 mm thick injection-moldedspecimen from a height of 1,000 mm, followed by measuring an averagedrop height. Next, whether the specimen satisfied Equation 3 is checked,thereby evaluating impact resistance. The specimen is rated as O whensatisfying Equation 3 and rated as X when not satisfying Equation 3:

1000 mm≤Id  [Equation 3]

where Id is a drop height measured on the 2 mm thick injection-moldedspecimen using the 1 kg metallic weight according to the DuPont droptest.

TABLE 2 Comparative Comparative Comparative Comparative Example 1Example 1 Example 2 Example 3 Example 4 Total light transmittance (%)83.84 92 80.58 81.25 83.56 Haze (%) 6.26 0.5 26.8 27.5 11.23 Surfaceresistance 2 × 10⁸ 2 × 10¹⁶ 1.2 × 10⁹ 8 × 10⁸ 2 × 10⁸ (Ω/□)Antibacterial properties 4.6 0 4.6 4.6 4.6 (Staphylococcus)Antibacterial properties 3.0 0 3.0 3.0 3.0 (Escherichia coli) DuPontdrop test ◯ X ◯ ◯ ◯ (Rubber, 0.5 kg) DuPont drop test ◯ X ◯ ◯ ◯ (Metal,1 kg) Appearance properties ◯ ◯ X X X Electrical suitability ◯ X X ◯ ◯Impact resistance ◯ X ◯ ◯ ◯

From the results of Table 2, it can be seen that the thermoplastic resincomposition of Example 1 exhibits good transparency, antistaticproperties, impact resistance and antibacterial properties and has agood balance therebetween. The thermoplastic resin composition ofExample 1 includes 100 parts by weight of the base resin including 14 wt% to 25 wt % of the (A) (meth)acrylate-aromatic vinyl-vinyl cyanidecopolymer and 75 wt % to 86 wt % of the (B) (meth)acrylate resin; and 25parts by weight to 35 parts by weight of the (C) antistatic resinincluding at least one of a polyether-ester amide block copolymer, apoly(alkylene) glycol and a polyamide, relative to 100 parts by weightof the base resin.

On the other hand, it can be seen that, since the thermoplastic resincompositions of Comparative Examples 1 to 4, which include an excess ofthe (A) (meth)acrylate-aromatic vinyl-vinyl cyanide copolymer andinclude an insufficient amount of the (B) (meth)acrylate resin, havenegative compatibility between the base resin and the antistatic resin,it is difficult to realize good electrical suitability, impactresistance, and/or appearance properties. In addition, the thermoplasticresin composition of Comparative Example 1 does not include theantistatic resin and has extremely high surface resistance, suffers fromcracking and could not exhibit antibacterial properties, and thus thethermoplastic resin composition of Comparative Example 1 is not suitablein terms of all of electrical properties, impact resistance, andantibacterial properties.

Example embodiments have been disclosed herein, and although specificterms are employed, they are used and are to be interpreted in a genericand descriptive sense only and not for purpose of limitation. In someinstances, as would be apparent to one of ordinary skill in the art asof the filing of the present application, features, characteristics,and/or elements described in connection with a particular embodiment maybe used singly or in combination with features, characteristics, and/orelements described in connection with other embodiments unless otherwisespecifically indicated. Accordingly, it will be understood by those ofskill in the art that various changes in form and details may be madewithout departing from the spirit and scope of the present invention asset forth in the following claims.

What is claimed is:
 1. A thermoplastic resin composition comprising:about 100 parts by weight of a base resin comprising about 14 wt % toabout 25 wt % of (A) a (meth)acrylate-aromatic vinyl-vinyl cyanidecopolymer and about 75 wt % to about 86 wt % of (B) a (meth)acrylateresin; and about 25 parts by weight to about 35 parts by weight of (C)an antistatic resin comprising at least one of a polyether-ester amideblock copolymer, a poly(alkylene) glycol and a polyamide, relative toabout 100 parts by weight of the base resin.
 2. The thermoplastic resincomposition according to claim 1, wherein a weight ratio of the (A)(meth)acrylate-aromatic vinyl-vinyl cyanide copolymer to the (B)(meth)acrylate resin in the base resin ranges from about 1:3 to about1:6.
 3. The thermoplastic resin composition according to claim 1,wherein the (A) (meth)acrylate-aromatic vinyl-vinyl cyanide copolymer isa copolymer of a mixture comprising about 20 wt % to about 40 wt % of anaromatic vinyl monomer and a vinyl cyanide monomer and about 60 wt % toabout 80 wt % of a (meth)acrylate monomer.
 4. The thermoplastic resincomposition according to claim 1, wherein the (C) antistatic resincomprises a polyether-ester amide block copolymer, the polyether-esteramide block copolymer comprising about 10 wt % to about 95 wt % of apolyether-ester block.
 5. The thermoplastic resin composition accordingto claim 1, wherein the base resin has an index of refraction of about1.25 to about 1.75.
 6. The thermoplastic resin composition according toclaim 1, wherein a difference in index of refraction between the baseresin and the antistatic resin is about 0.3 or less, as represented byEquation 1:Difference in index of refraction=|(R1−R2)|  [Equation 1] where R1 is anindex of refraction of the base resin and R2 is an index of refractionof the antistatic resin.
 7. The thermoplastic resin compositionaccording to claim 1, wherein the thermoplastic resin composition has anantibacterial activity of about 2.0 to about 7.0 against Staphylococcusand an antibacterial activity of about 1.0 to about 7.5 againstEscherichia coli, as calculated by Equation 2 after a 5 cm×5 cm specimenis inoculated with Staphylococcus and Escherichia coli, in accordancewith JIS Z 2801 for antibacterial evaluation:Antibacterial activity=log(M1/M2)  [Equation 2] where M1 is the numberof bacteria measured on a blank specimen after culturing at 35° C. and90% RH for 24 hours and M2 is the number of bacteria measured on thespecimen of the thermoplastic resin composition after culturing at 35°C. and 90% RH for 24 hours.
 8. The thermoplastic resin compositionaccording to claim 1, wherein the thermoplastic resin composition has ahaze of about 10% or less and a total light transmittance of about 80%or more, as measured on a 2.5 mm thick specimen in accordance with ASTMD1003.
 9. The thermoplastic resin composition according to claim 1,wherein the thermoplastic resin composition has a surface resistance ofabout 10×10⁸ Ω/□ or less, as measured on a 2.5 mm thick specimen at 23°C. and 50% RH in accordance with ASTM D250.
 10. The thermoplastic resincomposition according to claim 1, wherein the thermoplastic resincomposition satisfies Equation 3:1000 mm≤Id  [Equation 3] where Id is a drop height measured on a 2 mmthick injection-molded specimen using a 1 kg metallic weight accordingto the DuPont drop test method.
 11. A molded article produced from thethermoplastic resin composition according to claim 1.